OBJECTIVE We studied the relationship between an insertion/deletion (I/D) polymorphism in the ACE gene and albuminuria/proteinuria in Japanese NIDDM patients.

RESEARCH DESIGN AND METHODS A total of 142 Japanese NIDDM patients (89 men, 53 women) with a known diabetes duration of 14 ± 5 (mean ± SD) years and an age of 56 ± 6 years were divided into three groups according to the stage of nephropathy: 41 patients with normoalbuminuria, 47 patients with microalbuminuria, and 54 with overt proteinuria. The three groups were similar in age, diabetes duration, and recent HbA_1c level.

RESULTS The distribution of DD, ID, and II genotypes of the ACE gene did not differ among the three groups (10, 46, and 44% in the normoalbuminuric patients; 13, 53, and 34% in the microalbuminuric patients; and 15, 46, and 39% in the proteinuric patients, respectively). Meanwhile, the frequency of the D allele in the proteinuric male patients was slightly higher than in the normoalbuminuric male patients (45 vs. 27%, X 2 = 3.9, P < 0.05), while the D allele frequency was nonsignificantly lower in the proteinuric female patients than in the normoalbuminuric female patients.

CONCLUSION These results did not support the hypothesis that the genotype of the ACE gene would be a clinically useful genetic marker for predicting the development of nephropathy in Japanese NIDDM patients. However, the role of D allele of ACE gene in the progression of nephropathy in male patients remains to be seen.